Posted
by
timothy
on Thursday July 15, 2010 @09:36PM
from the elaborate-postponement dept.

bennyboy64 writes "An Australian company is developing a laser tracking system that will help prevent collisions between satellites and space debris, ZDNet reports. 'The trouble is it's [debris] in orbit and travelling at orbital speeds, which means that it is travelling at about 30,000 kilometres an hour," said the CEO of the Australian company. 'If even a tiny little piece runs into a satellite it'll destroy it or punch a hole through a person if they're out there space walking.'"

Electro Optic Systems' laser technology, with the help of a federal government grant, will enable the Mount Stromlo observatory in Canberra to track space junk and sell the data it collects to satellite owners and companies like NASA.

Reading the summary I had hopes they had a laser rocket thing worked out: you heat the leading edge of a bit of space junk. Gas comes off that side and pushes the fragment backwards so it re-enters the atmosphere. But no. Its just a better way to detect the particles.

Are they just making shit up or what? 30,000 mph is relative to the ground. Anything orbiting with be near that speed, including the space men. Someone tell me I'm wrong, and please tell me why. It seems to me the relative velocities would be small.

The particles you collide with could be in the same orbit but going the other way, though this is unlikely. More likely they could be in a different orbital plane so they sideswipe you at significant speed, or in an orbit with a different eccentricity so they have a decent relative velocity. Many particles cross each others paths with the speed of a fast bullet.

Sure, 30,000 mph is relative to the ground. The velocity of a piece of space junk relative to an astronaut could well be 60,000 mph if it's going the other way round. Even if both junk and astronaut are orbiting west-to-east, they could be on divergent ellipses. So collision speeds could go anywhere from 0 to 60,000 mph. Heck, I'm pretty sure that a collision at a velocity difference of "just" 1,000 mph would hurt.

There are certainly a few large bits and pieces that could probably be of great use to, say, hypothetical Mars explorers(the ISS, maybe a few of the larger junk satellites or upper rocket stages); but the overwhelming majority of the stuff is tiny little bits and pieces, zipping around at horrid velocities in a variety of orbits across a vast volume of space. By comparison the (fairly tenuous and soupy) Pacific garbage patch is practically solid, and it is all more or less sitting there, just waiting to be scooped up, rather than zooming around(plus, life is much easier when you can get your capture apparatus shipped in by boat, rather than by rocket).

They already have lasers that can often stop death. You'll find them in hospitals; lasers are used in all sorts of surgeries. My retina specialist used one on me that stopped blindness, [yahoo.com] although I later had to undergo traditional surgery (a vitrectomy) when the retina detached. I journaled about it here. [slashdot.org]